A computer system allocates buffers (buffer) to running processes, and each process accesses a respective buffer during running and reads data from or writes data into the respective buffer.
However, same data may be accessed by different processes; in this case, the computer system needs to copy data stored in a buffer of one process into a buffer of another process, so that the another process acquires the data by accessing the buffer of the another process. Specifically, a central processing unit (CPU) performs the copy operation.
Copying data between buffers of any two processes requires participation of a CPU. With an increasing number of functions that the computer system implements, interaction between processes becomes more frequent. Therefore, copying data causes relatively high CPU usage, and further affects working performance of the computer system.